The objective of this proposal is to couple novel technologies to the microfluidic systems being developed in the Consortium on Human Islet Biomimetics (CHIB). These technologies will be connected to the CHIB devices in a modular format and will allow near real-time monitoring of insulin secretion. The rationale for performing this work is that with these technologies, the goals of CHIB and the Human Islet Research Network (HIRN) will be accomplished more quickly. The objective of this proposal will be accomplished by pursuing three specific aims that build in order of increasing sensitivity and modularity: 1) Utilize a fluorescence anisotropy immunoassay method for monitoring insulin secretion; 2) Employ an electrophoretic immunoassay device for high sensitivity insulin measurements; 3) Develop and incorporate an electrochemical sensor for monitoring insulin release in situ on the microfluidic systems. Under the first aim, an all-optical assay for measurement of insulin release will be incorporated into the output of the CHIB device. This assay will provide an expedited path to monitoring insulin release from islets. In the second aim, a method to couple the output of the CHIB device to a high sensitivity assay for measurement of insulin secretion dynamics is presented. The advantage of this method compared to that from the first is higher sensitivity, allowing not only insulin levels but also their patterns to be discerned. In the third aim, an electrochemical aptasensor will be developed for insulin. This method will facilitate in situ measurement of the insulin while in the future leading to an integrated system with this biosensor. The proposed research aims are innovative because they will provide the first means for the teams within CHIB and HIRN to monitor hormone release from islets in near real-time. To the best of our knowledge, there are no teams within CHIB or HIRN that have these capabilities. The new collaboration between the various laboratories within this proposal is a combination of engineering and analytical chemistry which will provide unique opportunities for future investigations. The results will provide a significant improvement in HIRN?s ability to fulfill its overall mission to ?support innovative and collaborative translational research focused on understanding how human beta cells are lost in Type 1 diabetes and finding innovative strategies to protect and replace functional beta cell mass in humans.?